Making chromated blood products for use in alkaline blood glues of high viscosity



Dec. 10, 1968 J. HOHBACH E AL 3,415,668

MAKING CHROMATED BLOOD PRODUCTS FOR USE IN ALKALINE BLOOD GLUES OF HIGH VISCOSITY Original Filed Nov. 9, 1964 VISCOSITIES OF BLOOD GLUES CONTAINING BEEF BLOOD TREATED WITH VARYING PERCENTAGES OF SODIUM CHROMATE (POISES AT 12 F.

GLUE VISCOSITY AGE or LIQUID BLOOD (HouRs) BEFORE SPRAY DRYING DALE J. HOHBACH RON NlE D. DAVIS INVENTORS BY fay L920? ATTY.

United States Patent MAKING CHROMATED BLOOD PRODUCTS FOR USE IN ALKALINE BLOOD GLUES OF HIGH VISCOSITY Dale J. Hohbach and Ronnie D. Davis, Hillsboro, Oreg., assignors to Pacific Adhesives Company, Inc., a corporation of Oregon Continuation of application Ser. No. 409,815, Nov. 9, 1964. This application Jan. 22, 1968, Ser. No. 699,742

13 Claims. (Cl. 106-146) ABSTRACT OF THE DISCLOSURE A chromated blood product for use in the manufacture of alkaline blood glues of stable viscosity is made by declotting freshly drawn animal blood. Within 12 hours from drawing, the declotted blood is reacted with from 0.01- 30% by weight of a water-soluble, inorganic hexavalent chromium compound. The reaction is carried out at a temperature of between the freezing temperature of the mixture and the coagulating temperature of the blood and at a pH between the acid coagulation pH and the alkaline gelling pH of the blood. When the chromated blood product thereafter is employed in making a blood glue, it imparts to the glue a viscosity substantially greater than the inherent viscosity of a glue, made from unchromated blood of the same type and source, and of the same age after drawing.

This application is a continuation of Ser. No. 409,815, filed Nov. 9, 1964, now abandoned.

This invention relates to a process of making a blood product for use in the manufacture of alkaline blood glues.

The usual procedure for making blood glues comprises collecting animal blood from the slaughterhouse floor, declotting the blood and spray drying it to form a soluble blood glue base.

The glue base is transported to the glue manufacturing plant where it is formulatedinto the finished gl-ue by mixing it with water and such glue-base-dispersing chemicals as sodium silicate, caustic soda, lime, and an anti-foaming agent. Soya meal, other proteins and fillers, also may be included in the formulation, if desired.

The viscosity of the resulting glue is determined largely by the nature of the blood glue base, and itself determines, in turn, the amount of Water which may be included in the glue mix. In general, where a particular blood glue base has high viscosity-imparting properties, a correspondingly large amount of water may be employed without sacrifice of glue spreadability, adhesive qualities and other desirable properties. Accordingly, blood products which impart a high degree of viscosity and good stability to blood glues in which they are incorporated, are highly desired by the glue maker.

Heretofore the viscosity-imparting characteristics of blood glue bases regrettably have been non-uniform, nonpredictable, and dependent upon two principal factors.

The first such factor is the animal species from which the blood is obtained. The blood of cattle, for example,

Patented Dec. 10, 1968 ice has high viscosity-imparting characteristics while the blood of swine is deficient in that property.

The second such factor is the treatment the blood receives in the slaughterhouse. Immediately upon exposure to the atmosphere the blood loses with astonishing rapidity its desirable property of imparting high viscosity levels to glues in which it is incorporated.

We have discovered, and it is the essence of the present invention, that the processes which deteriorate the viscosity-imparting qualities of animal blood upon contact with the atmosphere may be arrested, and a blood product of uniformly high viscosity-imparting properties obtained, by the simple expedient of mixing with the blood as soon as possible after it has been drawn from the animal a relatively small proportion of a water-soluble, hexavalent, inorganic chromium compound. The blood thereby is rendered relatively stable to deterioration and thereafter may be spray dried or otherwise converted to a glue-making blood base of uniform and highly desirable viscosity-imparting properties.

This desirable result is obtained without sacrafice of other glue properties. Also, it makes possible upgrading bloods such as swine blood to such an extent that they may be employed as satisfactorily as the blood of cattle in the formulation of commercial blood glues.

Considering the foregoing in greater detail:

In carrying out the process of our invention, animal blood is collected and processed as soon as possible after it has been obtained. To achieve the desired results, it must be processed within a time period of 12 hours, preferably within a period of 2 hours, after it has been withdrawn from the animal.

First the blood is declotted to facilitate its subsequent reaction with the chromium compound, as well as to facilitate the spray drying operation by which it preferably is dehydrated.

The declotted liquid blood then is introduced immediately into a suitable reaction vessel equipped with means for agitation. There it is treated at once with one or more of the chromium compounds which have been found to be especially suitable for the intended purpose. These are the hexavalent inorganic chromium compounds having sufficient water solubility (at least .002 g./ ml. of water at 20 C.) to dissolve appreciably in the aqueous reaction medium. Suitable chromium compounds accordingly are: aluminum chromate, ammonium chromate, calcium chromate, copper chromate, lithium chromate, magnesium chromate, potassium chromate, sodium chromate, zinc chromate, ammonium dichromate, copper dichromate, lithium dichromate, potassium dichromate, sodium dichromate, chromic acid.

A very small amount of chromium compound imparts to some degree the desired viscosity-improving characteristics, i.e. an amount of as little as 0.01% by weight, expressed as sodium chromate, and based on the weight of the blood solids. On the other hand, the introduction of more than about 30% by weight of chromium compound induces undesirable side reactions and increases the difficulty with which the treated mixture subsequently may be handled. Accordingly the range of use of the chromium compound lies within the broad range of from 0.01- 30.00% by weight, preferably within the range of from 0.0l5.0% by weight.

The temperature within the reaction vessel should be maintained at a level which is above the freezing temperature of the mixture, but below the coagulating temperature of the blood, i.e. from 32120 F. Slaughterhouse blood normally has a temperature of from 90-100 F. Blood at this temperature may be employed in the instant process without temperature adjustment.

The pH of the blood treating mixture should be maintained at a level which is above the acid coagulating pH, but below the alkaline gelling pH of the blood. The treating pH thus lie-s within the range of pH 5 and pH 10. When slaughterhouse blood handled in the usual manner is treated with chromium compounds of the character and in the amount stipulated herein, the treating mixtures will generally have a pH level falling within a range of from pH 5 to 10. However, if pH adjustment is required, suitable amounts of the conventional acidic or alkaline buffering agents may be employed.

The treatment with the chromium compound in the indicated amount at the indicated temperature and pH is carried out with agitation until the reaction which occurs has been completed. The reaction time is determined to some extent by the temperature of the reaction mixture. In general, however, a reaction time of from 5 minutes to 3 hours is sufficient to complete the reaction.

After the reaction is complete, the resulting chromated blood is comparatively stable against further degradation and hence need not be dehydrated immediately. Thereafter in accordance with established plant schedules, it may be processed for removal of water and conversion to a solid blood product. However, it need not be dehydrated at all if glue is to be made from it within its viscositystable time period.

If the chromated blood is to be dehydrated, water removal may be accomplished by any of the usual techniques which neither degrade nor destroy the blood. Thus it may be dried on a heated vacuum drum by the usual techniques. Preferably, however, it is spray dried by atomizing it and mixing it with hot air at a temperature which is sufficient to dry the blood rapidly, while still leaving it dispersible in alkaline glue making mixtures. This may be accomplished, for example, by mixing it with air at a temperature of from 300-500 F. at the time of introducing the liquid blood into the drier, and retaining it in the drier for a time period of from 2 to 20 seconds.

The dried, chromated blood then may be sacked and stored under usual atmospheric conditions for any desired length of time without danger of loss of its glue-making properties.

After being passed through the channels of commerce, the chromated blood may be formulated into alkaline blood glue having a pH of more than 7 by the glue manufacturer, or the plywood manufacturer, by mixing it with the usual glue making chemicals. These may include protein-dispersing agents such as sodium silicate, caustic soda, and lime; pine oil and other anti-foaming agents; fillers such as wood flour, bark powder and walnut shell flour; and proteins other than blood, such as soya flour, cottonseed meal, peanut meal, fish meal and casein; all used in proportions calculated to produce a glue of desired properties. Typical glue formulations which may be mixed and applied in the usual manner are given in Tables I and 11 below.

TABLE I Parts by weight Glue-making protein consisting of 5l00% by weight of chromated animal blood, and

095% by weight of other glue-making protein 100 Dispersing agent for dispersing glue-making proteins in aqueous media 1465 Alkaline-blood-glue filler 0l50 Water 601200 4 TABLE II Parts by weight Glue-making protein consisting of 5l00% by weight of chromated animal blood and 095% by weight of other glue-making protein 100 Alkali metal caustic 5-15 Alkali metal silicate 10100 Lime 535 Alkaline-blood-glue filler 10l00 Water 60l200 The presently described process of making a chromated blood glue base is indicated in the following examples, wherein parts are given in parts by weight.

Example 1 This example illustrates the effect of using sodium chromate in varyings amount on the viscosity-imparting qualities of a blood glue base in which it is incorporated.

Within three hours from the blood letting time, separate samples of declotted beef blood were reacted with sodium chromate, used in amounts of 0.05%, 0.09%, 0.2%, 0.5% and 1.0% by weight, based on the weight of blood solids. An unchromated blood control sample also was provided.

The samples had a pH within the range of from pH 5 10. They were mixed with the sodium chromate at a temperature of F. and thereafter agitated and maintained at that temperature level for a total period of up to 96 hours. Periodically during this time, samples were withdrawn, spray dried and tested for the effect of the addition of the sodium chromate on the viscosity-imparting characteristics of the blood. These were determined by formulating samples of the chromated blood into alkaline blood glue samples having the following generic composition:

Parts by weight Chromated blood 60 Soya meal 60 Sodium silicate (41 B.) 44 Caustic soda (36% by weight solution) 21 Lime (33 /3 by weight aqueous slurry) 30 Water 693 The glue samples thus prepared were tested for viscosity at 72 F. by the 5 minute Brookfield viscosity test, using a Brookfield RVF viscosimeter at 20 r.p.m. with spindle No. 6. The results are shown in the graphs, which comprise the single figure of the drawings. These show the change in viscosity of glues made from blood samples which had been treated with sodium chromate and then allowed to age for several hours, during which time samples periodically were withdrawn, spray dried, formulated into glues, and the viscosity of the glues determined and recorded.

Curve A, the curve of the control sample, illustrates the drastic loss of viscosity-imparting qualities when blood is allowed to stand even for a few hours without being treated with chromium compound in the manner described herein.

Curves B, C, D, E and F illustrate the progressively sta bilizing effects of adding increased amounts of chromium compound to the blood. Curve F indicates that when 1% chromium compound is added to the blood, its viscosity stabilizing characteristics become almost a straight line function of time, there being almost no change in viscosity for a time period of as much as two days.

Examples 213 The procedure of Example 1 was repeated, using as blood chromating agents 0.2% by weight of various water-soluble, hexavalent, inorganic, chromium compounds. The temperature was 75 F. and the maximum duration of reaction of the blood was 96 hours. The 5 minute viscosities of glues made from the chromated blood products were as follows:

Chromium compound Ageaot tilood 5 minute glue viscosity Aluminum ehromate (Ex. 2) 50 126 120 93 Ammonium ohromate (Ex. 3)-... 2 207 6 225 22 220 46 210 54 120 96 55 Calcium ohromate (Ex. 4) 43% 25;) Copper chromate (Ex. 5) 4g% 12g Lithium Chromate (Ex. 6) Magnesium Ohromate (Ex. 7) 138 2258 Potassium chromate (Ex. 8) 3 220 23% 205 47 235 76 95 94 43 Zinc chromate (Ex. 9) 43 5 12: Copper dichromate (Ex. 10) 48 192 119 173 Lithium dichromate (Ex. 11) 48 247 98% 101 Sodium dichromate (Ex. 12) 2 208 12% 234 24 232 30 153 54 146 78 70 Chromic acid (Ex. 13) 3 222 23 260 54 128 70 61 Thus it will be apparent that by the present invention, we have provided a process for making a blood product, useful in the manufacture of alkaline blood glues, which has many advantages. It preserves the viscosity-imparting qualities of the blood for long periods of time. It insures that the viscosity qualities of the blood will be uniform from batch to batch, thereby insuring uniformity in the finished glue. It improves the economy of the gluing operation in that it permits the manufacture of glues having a higher proportion of water without sacrifice of glue properties.

All of these advantages are obtained, furthermore, by a procedure which requires no special equipment, which may be included handily in the usual blood processing routine, which does not affect the blood adversely in any Way, and which does not add significantly to the cost of manufacture of the blood product.

Having thus described our invention in preferred embodiments we claim:

1. The process of making a chromated blood product for use in the manufacture of alkaline blood glues of improved viscosity which comprises:

(a) declotting freshly drawn animal blood, and

(b) within 12 hours from the time of drawing the blood from the animal reacting the declotted liquid blood with from 0.01-30% by weight, based on the weight of the blood solids of at least one member of the group consisting of the chromates of aluminum, ammonium, calcium, copper, lithium, magnesium, potassium, sodium, and zinc; the dichromates of ammonium, copper, lithium, potassium and sodium; and chromic acid,

(c) at a temperature of between the freezing temperature of the mixture and the coagulating temperature of the blood,

(d) at a pH of between the acid coagulation, pH and the alkaline gelling pH of the blood,

(e) the resulting chromated blood product being characterized by the property of imparting to alkaline blood glues in which it is incorporated a viscosity substantially greater than the inherent viscosity of a. glue of the same composition, made from unchromated blood of the same type and source, and the same age after drawing.

2. The process of claim 1 wherein the chromium compound is sodium chromate.

3. The process of claim 1 wherein the chromium compound is sodium dichromate.

4. The process of claim 1 wherein the chromium compound is chromic acid.

5. The process of claim 1 wherein the chromium compound is employed in the amount of from 0.01-5.0% by weight.

6. The process of claim 1 wherein the temperature is between 32 and 120 F.

7. The process of claim 1 wherein the pH is between pH 5 and pH 10.

8. The process of claim 1 including the step of spray drying the reaction mixture to form a solid, chromated blood product.

9. The chromated blood product of claim 1.

10. The process of making a chromated blood product for use in the manufacture of alkaline blood glues of improved viscosity which comprises:

(a) declotting freshly drawn animal blood, and

(b) within 12 hours from the time of drawing the blood from the animal reacting the declotted liquid blood with from 0.01-5.0% by weight, based on the weight of the blood solids of at least one member of the group consisting of the chromates of aluminum, ammonium, calcium, copper, lithium, magnesium, potassium, sodium and Zinc; the dichromates of ammonium, copper, lithium, potassium and sodium; and chromic acid,

(c) at .a temperature of from 32120 F.,

(d) at a pH of from 5-10,

(e) the resulting chromated blood product being characterized by the property of imparting to alkaline blood glues in which it is incorporated a viscosity substantially greater than the inherent viscosity of a glue of the same composition, made from unchromated blood of the same type and source, and the same age after drawing.

11. A chromated blood glue of improved viscosity comprising:

Parts by weight Glue-making protein consisting of 5-100% by weight of animal blood chromated by reaction within 12 hours from the time of withdrawing the blood from the animal with from 0.01-

30% by weight, based on the weight of the blood solids of at least one member of the group consisting of the chromates of aluminum, ammonium, calcium, copper, lithium,

magnesium, potassium, sodium, and zinc; the

dichromates of ammonium, copper, lithium, potassium and sodium; and chromic acid;

and 0-95 by weight of other glue-making protein Dispersing agent for dispersing glue-making proteins in aqueous media l-465 Alkaline blood glue filler 0-l50 Water 60-1200 The glue having a viscosity substantially greater than the inherent viscosity of a glue of the same composition made from unchromated blood of the same type and source and the same age after drawing.

12. A chromated blood glue of improved viscosity comprising:

Parts by weight Glue making protein consisting of 5-100% by weight of animal blood chromated by reaction within 12 hours from the time of withdrawing the blood from the animal with from 0.01-

5% by weight, based on the weight of the blood solids, of at least one member of the group consisting of the chromates of aluminum, ammonium, calcium, copper, lithium,

magnesium, potassium, sodium, and zinc; the dichromates of ammonium, copper, lithium, potassium and sodium; and chromic acid; and 095% by weight of other glue-making protein 100 5 Alkali metal caustic 5-15 Alkali metal silicate 10-100 Lime 5-35 Alkaline blood glue filler 10-100 Water 60-1200 10 The glue having a viscosity substantially greater than the inherent viscosity of a glue of the same composition made from unchromated blood of the same type and source and the same age after drawing.

13. The glue of claim 12 wherein the alkali metal caustic comprises caustic soda and the alkali metal silicate comprises sodium silicate.

No references cited.

JULIUS F ROME, Primary Examiner.

T. MORRIS, Assistant Examiner.

US. Cl. X.R. 

